1. Technical Field
Embodiments described herein are related to the field of integrated circuit implementation, and more particularly to the implementation of clock synchronization circuits.
2. Description of the Related Art
Computing systems may include one or more systems-on-a-chip (SoCs), which may integrate a number of different functions, such as, graphics processing, onto a single integrated circuit. With numerous functions included in a single integrated circuit, chip count may be kept low in mobile computing systems, such as tablets, for example, which may result in reduced assembly costs, and a smaller form factor for such mobile computing systems.
System-on-a-chip (SoC) designs may have multiple clock sources, each operating at a different frequency to support one or more functions. A given functional block within an SoC, such as, for example, an Universal Serial Bus (USB) module, an Ethernet module, a graphics processor, or an audio processor, may utilize two or more clock signals with different frequencies for proper operation. In such cases, logic that is clocked by the clock signal with a slower frequency may need to enable or disable a local portion of the clock signal with a higher frequency. To avoid clock glitches and/or a metastable signal, the enable signal from the slow frequency clock domain may be synchronized to the high frequency clock domain by using a synchronizing circuit. When the local high frequency clock is disabled within the functional block, a global version of the high frequency clock may continue to clock the synchronizing circuit, which may consume power needlessly.